Display screen or portion thereof with a graphical user interface for a test platform



FIG. 1 is a front view of a display screen or portion thereof with a graphical user interface for a test platform, showing our new design.

FIG. 2 is an enlarged view of a left region of the display screen or portion thereof of FIG. 1, shown separately for clarity of illustration.

FIG. 3 is an enlarged view of a central region of the display screen or portion thereof of FIG. 1, shown separately for clarity of illustration; and,

FIG. 4 is an enlarged view of a right region of the display screen or portion thereof of FIG. 1, shown separately for clarity of illustration.

The outermost broken-line perimeter in FIG. 1 illustrates the display screen or portion thereof and forms no part of the claimed design. The remaining broken lines in the drawings illustrate portions of the graphical user interface and form no part of the claimed design. 

CLAIM The ornamental design for a display screen or portion thereof with a graphical user interface for a test platform, as shown and described. 